To be totally correct, nothing is "illegal" on the Internet except those laws that apply internationally to all countries, but those laws do not apply to individuals and companies — only governments.

The Internet is an international network instead has a different model of administration, where the stakeholders — network operators (ISPs, universities, companies), system administrators, network engineers, website owners, web developers, users all alike have say in how the net is run. This is why it's important for everyone, including everyone on this site to speak on strong issues and to collaborate as to protect principles that makes the Internet what it is. To protect this bottom-up administration of the network.

The Internet is operated on the principle of standards, these standards are sometimes informal, some are formal but all in all they are standards that interested stakeholders have decided so. In order to change the Internet, you need to convince people.

If something goes against the general consensus, it is filtered, worked around or routed around. This is why governmental censorship is generally ineffective to the global network. The network on all levels deems this censorship a fault and routes around it. If someone transmits spam or phishing links stakeholders like mailserver operators and website operators proceed to filter out that. If advertisements are becoming overbearing and abusive, users simply refuse to have their computers request them. If there's route hijacking going on the perpetrator network is removed from the network until they stop. The Internet has millions.. billions of eyes on it at any one moment.

This is why the Internet was able so strongly to go up against SOPA/PIPA, because those bills produced by the US Government were deemed against the consensus of the network and thus couldn't be made standard.

In regards to false advertisement and bad marketing, the Internet is through discussions like this very thread is collaborating and asking the right questions, starting the standardization process to decern "what is good" and "what is bad" — a discussion that is far overdue.

As to my own perspective, I think we need to keep the Internet as open as possible, as such legislation in any country will not do that, only standardization and information about these issues and a course of action to act to bring rectification. We as netizens need to hold advertisement networks to account, to call them out on their lack of action, to name and shame if we need be. But we have to be careful too, not to bring about witch-hunts, that's not constructive. We need to keep pressure against the ad networks and publishers who engage in bad ads.

We need to bring the ad networks out from behind the websites they advertise on.